Process of manufacturing india-rubber tires.



No. 640,644. Patented Ian. 2, I900.

H. FALCONNET &. M. PEBUDEAUD'.

PROCESS OF MANUFACTURING INDIA RUBBER TIRES.

I (Applicatiqn filed. Nov. 9, 1899.) (No Model.)

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ATTORNEYS wnorouwo. WASHINGTON a c UNITED STATES PAT NT Fries.

HENRI FALOONNET AND MAURICE PERODEAUD, or oHoIsY-sUR-sEiNE, FRANCE.

i RooEss OF MANUFACTURING INDIA-ZRUBBER TIREs;

SPECIFICATION forming part of Letters Patent No. 640,644, dated January2, 1900.

Application filed November 9, 1899.

To all whom it may concern:

Be it known that we, HENRI FALOONNET and MAURICE PERODEAUD, citizens ofthe Republic of France, and residents of Ohoisy-sur- Seine, in theRepublic of France, have invented certain new and useful Improvements inProcesses of Manufacturing India-Rubber Tires for the Wheels of Vehiclesand other Like Articles, of which the following is a full, clear, andexact specification.

The conditionswith which a wheel-tire must comply are difficult torealize in practice, be-

cause they are up to a certain point contra dictory. The difficultieswhich are encountered in order to give the tire resiliency andflexibility, on the one hand, and, on the other hand, the power toresist the various strains of traction, compression, friction, cutting,tearing, and the like may well be conceived. Logically, when tires areemployed which are entirely resilient it is preferable to give them acertain amount of resistance, and conse quently a relative rigidity atthe external periphery, more particularly at the points where they arein contact with the ground and where they receive the reaction of thelatter and the action of the weight of the vehicle transmitted by thewheel on which this tire is fixed. On the other hand, the central partof the tire must have great elasticity. These conditions are wellrealized by pneumatic tires; but the want of strength of these latterrenders their use difficult and even dangerous in the case of heavyvehicles. Eflorts have been made to make solid resilient tires, andthese tires have been composed of layers of different materials ofvariable elasticity combined by various processes of adhesion grouping,and fixing. Such tires have only a relative cohesion.

The invention which forms the object of the present application relatesto a solid-rubber tire obtained by means of a single original substance,such as pure commercial rubber or a mixture of same converted (after itsmanufacture into a tire) by a special process enabling a resiliency orflexibility to be imparted to it which increases from the periphery tothe center. Thus, assuming, for instance, that we start with ahomogeneous tire Serial No. 736,599. (N specimens.)

our invention consists in subjecting the tireformed by known industrialmethods to a series of vulcanizations alternating with subsequentrefrigerations, the number of alternate operations corresponding to thenumber of zones of different flexibility, such as a b c, which it isdesired to form in the tire. Our method is preferably employed with anindiarubber as far as possible free from mineral substances which aregood conductors of heat.

The prepared tire p is heated at first to the temperature of 110centigradethatis to say, to about the maximum temperature necessary forproducing a vulcanization. This first slight vulcanization is extendedto the whole nlass p, and for this object We maintain this temperatureuntil the vulcanization has had time to spread from the periphery to thecenter. Then we congeal the vulcanized tire for the first time in arefrigerating apparatus at a temperature varying between 10 and 20centigrade. WVe maintain that temperature until the temperature is thesame throughout the whole tire. The tire of which the whole mass iscongealed is then vulcanized afresh and for this object carried to atemperature higher than in the first case-say to 150 centigrade. Thistemperature is not maintained long enough for the fresh vulcanization ofthe tire to spread to the axial zone a, in which we thus create a sortof reserve of cold, the bad conductibility of india-rubber facilitatingthis phenomenon. A tire the manufacture of which is interrupted at thismoment will then comprise two zones of different flexibilityviz., theaxial zone 0, which is Very flexible, and a peripheral zone of a lessflexibility extending from the part c to the surface.

In order to divide the mass extending from c to the periphery into azone I) of greater flexi- 7 center to be obtained in the mass of a tireis according to the number of zones which it is bility thanlthe outerzone a, it is sufiicient, after the second vulcanization at hightemperature, to con geal the tire afresh and then to subject it to athird vulcanization for a time short enough for the heating to remainconfined to the layer a, by reason of the reserve of cold in the otherlayers. \Ve lay stress on this point that the successive vulcanizationsmust necessarily alternate with congealations, and it is thesealternations which enable the improved result indicated by us to beattained. As regards the number of these alternations and theirdurations, of course they may vary desired to produce in the massof thetire by reason of the special uses to which the tire is to be put andaccording to the degree of flexibility, resiliency, or resistance whichit is desired to obtain.

Although this process enabling zones of a flexibility increasing fromthe periphery to the more particularly applicable for a tire preparedindustrially from a homogeneous mass, it may also be employed with atire prepared with fragments of difierent substances joined together byadhesion and pressure by any of the known methods.

We claim as our invention The process of manufacturing indie-rubbertires for the wheels of vehicles and other like articles which consistsin creating, in the mass of the tire, zones of different resiliency orflexibility increasing from the periphery to the center, by subjectingthe tire formed by the ordinary industrial methods and subjected to afirst generalyulcanizatmn, to a series of refrigerations, attemperaturesbelow zero, alternating with vulcanizations at high temperature ofincreasingly shorter duration, whereby the vulcanization interrupted bythe congealing of the core of the tire, is efiected to decreasingdepths, substantially as hereinbefore set forth.

In witness whereof We have hereunto set our hands in presence of twowitnesses.

HENRI FALCONNET. MAURICE PERODEAUD.

Witnesses: V

EDWARD P. MACLEAN, ANDRE Mosrrcnnn.

